How does one represent the empty char?

Question

I\'m currently writing a little program but I keep getting this error when compiling

error: empty character constant

I realize i

Answer 1

String before = EMPTY_SPACE+TAB+"word"+TAB+EMPTY_SPACE;

Where EMPTY_SPACE = " " (this is String) TAB = '\t' (this is Character)

String after = before.replaceAll(" ", "").replace('\t', '\0');

means after = "word"